Welcome to Mobileread.
I don't believe there is a way to do what you want to do, but every time I think that, I'm proved wrong. The main developer is away for a few more days. Maybe someone else will stop by and prove me wrong.
Good Luck.
Moderator NoticeMoved the thread to general calibre forum. The development forum is not the place to ask general questions. Please read the "
PLEASE READ BEFORE POSTING - The purpose of this subforum" sticky post from the top of the Development forum.
For those new to the forum at the top of all calibre forums are sticky posts with information on many frequently asked questions.